Using grill pan or directly on grill, cook two celery sticks and strawberries until soft with grill marks on either side.
While celery and strawberries grill, make dressing. In jar, mix orange juice, lemon juice, Dijon mustard, honey, olive oil and salt.
Cut grilled and remaining raw celery sticks at angle into 1/4-inch pieces.
In mixing bowl, toss celery, strawberries, blackberries, blueberries, raspberries, burrata, arugula and hemp seeds with dressing. Mix well.